It is common in the formation of medical products containers, such as blood bags or blood filtration housings containing filters, to form an opening in the peripheral seal of the container. Such openings may be in the form of a preformed tube that is heat sealed into the periphery of such a container. An example of such an opening is shown in European Patent Publication No. 526678 published Feb. 10, 1993, in which shows ports molded into the seal of such a container formed of two peripherally sealed halves. Alternatively, ports have been molded into a wall panel and oriented at a 90.degree. angle to the plane of the panel.
Examples of filtration systems to remove white blood cells by filtration, for example, within the context of conventional multiple blood bag closed system configurations are described in Wisdom U.S. Pat. Nos. 4,596,657 and 4,767,541, as well as in Carmen et al U.S. Pat. Nos. 4,810,378 and 4,855,063. In these arrangements, an in-line white blood cell filtration device is used. Other such systems are described in Stewart U.S. Pat. No. 4,997,577. In these filtration systems white blood cells are removed as the red blood cells are conveyed to a transfer container. An example of a material used as a filter is set forth in Heagle et al U.S. Pat. No. 5,190,657 granted Mar. 2, 1993.
A need has existed for an improved opening port for plastic container walls used for a wide variety of purposes including such white blood cell filters. A particular need has existed for a form of a fluid pressure resistant outlet that can be formed tangentially in a flexible wall of a container.